Undoubtedly other species will be discovered that also exhibit this full range of characteristics. Many of these features are already known to characterize Stumptail Macaque sexuality, for example, including hidden estrous cycles (cf. de Waal 1989:150), anal and oral intercourse, and pairlike “sexual friendships” or “preferred partners” (and much remains to be learned about this species in the wild). Similarly, Japanese Macaques have pair-bonded consortships, face-to-face sexual encounters, and “social class” differences in sexual/pairing activity (cf. Corradino 1990:360), while Gorillas have face-to-face copulation, bonding or “preferred partners,” hidden estrous cycles (cf. Wolfe 1991:125), and oral sexual activities. Certain of these characteristics also occur individually in animal groups other than primates and cetaceans: a face-to-face mating position, for instance, is occasionally used by snow leopards, while Ruffs have a highly structured “class” system among males involving (among other features) differing sexual behaviors (Freeman, H. [1983] “Behavior in Adult Pairs of Captive Snow Leopards [
42
Weinrich,
43
Likewise, the durations of homosexual as opposed to heterosexual acts (such as mounting) are usually comparable. In some species, however, homosexual interactions generally last longer (e.g., Gorillas, White-handed Gibbons, American Bison, West Indian Manatees), while in others heterosexual encounters typically last longer (e.g., Harbor Seals, Red Foxes, Humboldt Penguins, Long-tailed Hermit Hummingbirds). In many species homosexual interactions do exhibit greater variability or flexibility in terms of the role differentiation of partners (see chapter 4 for further discussion).
44
Bonobo (Kitamura 1989:53—57, 61; Kano 1992:187); Gorilla (Fischer and Nadler 1978:660—61; Yamagiwa 1987a:12—14, 1987b:37; Harcourt and Stewart 1978:611—12); Hanuman Langur (Weber and Vogel 1970:76; Srivastava et al. 1991:496-97).
45
Japanese Macaque (Hanby and Brown 1974:164; Hanby 1974:838-40).
46
Flamingo (C. E. King, personal communication).
47
The head-to-tail position does occur in interspecies homosexual interactions with Tucuxi Dolphins. Same-species versus cross-species differences in mounting position (independent of the sex of the partner) are also found in other cetaceans. Among Bottlenose Dolphins, for example, a belly-to-belly mating position is typical of same-species contacts, both homosexual and heterosexual (cf. McBride and Hebb 1948:115, among others), while a sideways, dorsoventral position occurs in interspecies encounters with Atlantic Spotted Dolphins of both sexes (Herzing and Johnson 1997:92, 96).
48
Anderson, S. (1993) “Stitchbirds Copulate Front to Front,”
49
Vasey, “Homosexual Behavior in Primates,” p. 195.
50
For further details see the primate profiles in part 2, as well as the discussion of nonreproductive heterosexualities in chapter 5.
51